Separate Music Instrument wise from a song.

[safdarz]

I want to separate the music from a song and then break that music according to instruments played...Is it possible to do this, if YES then please advice how to do this...?

[Answerprancer]

Unless you have a copy of the original multi-track recording, you will be limited by the amount of instruments and the vocal setup (assuming that by "song" you mean a vocal track).
The only way you can divide an already mixed recording into its constituent parts -to my knowledge- is if a) you have TWO sounds perfectly split across the stereo field (eg. Buffalo Girls by Malcolm McLaren) or b) it's something very simple eg. voice and guitar, then you need to use the 'noise reduction' function of something like Adobe Audition.

[saxy_jag]

I don't know how easy it is to take an MP3 or other music file and make it into a midi. Once you've got a midi then you can run it through a notation programme to get the notation and then take the individual lines back into a sound format. BUT ... it's a long-winded way of doing it - if you even can. You need to be able to read music, for a start, and you won't get a true representation of the original at all.

I think Answerprancer's answer is correct, though.